Untrained Males Research Articles

Resistance training with different repetition duration to failure: effect on hypertrophy, strength and muscle activation.

BackgroundThis study investigated the effects of two 14-week resistance training protocols with different repetition duration (RD) performed to muscle failure (MF) on gains in strength and muscle hypertrophy as well as on normalized electromyographic (EMG) amplitude and force-angle relationships.MethodsThe left and right legs of ten untrained males were assigned to either one of the two protocols (2-s or 6-s RD) incorporating unilateral knee extension exercise. Both protocols were performed with 3–4 sets, 50–60% of the one-repetition maximum (1RM), and 3 min rest. Rectus femoris and vastus lateralis cross-sectional areas (CSA), maximal voluntary isometric contraction (MVIC) at 30o and 90o of knee flexion and 1RM performance were assessed before and after the training period. In addition, normalized EMG amplitude-angle and force-angle relationships were assessed in the 6th and 39th experimental sessions.ResultsThe 6-s RD protocol induced larger gains in MVIC at 30o of knee angle measurement than the 2-s RD protocol. Increases in MVIC at 90o of knee angle, 1RM, rectus femoris and vastus lateralis CSA were not significant between the 2-s and 6-s RD protocols. Moreover, different normalized EMG amplitude-angle and force-angle values were detected between protocols over most of the angles analyzed.ConclusionPerforming longer RD could be a more appropriate strategy to provide greater gains in isometric maximal muscle strength at shortened knee positions. However, similar maximum dynamic strength and muscle hypertrophy gains would be provided by protocols with different RD.

Three weeks of passive and intervallic heat at high temperatures (100±2 °C) in a sauna improve acclimation to external heat (42±2 °C) in untrained males

Currently, the effect of passive heat acclimation on aerobic performance is still controversial. Therefore, this study aimed to observe the effect of passive and intervallic exposure to high temperatures (100±2°C) in untrained males. Forty healthy untrained men participated in this investigation. They were randomised into a Control Group (CG; n=18) and an Experimental Group (EG; n=22). Both groups performed maximum incremental tests until exhaustion in normothermia (GXT1; 22±2°C), and 48h afterwards, in hyperthermia (GXT2; 42±2°C). The EG performed 9 sessions of intervallic exposure to heat (100±2°C) over 3 weeks. Subsequently, both groups performed two maximal incremental trials in normothermia (GXT3; 22±2°C) and 48h later, in hyperthermia (GXT4; 42±2°C). In each test, the maximal ergospirometric parameters and the aerobic (VT1), anaerobic (VT2) and recovery ventilatory thresholds were recorded. The Wilcoxon Test was used for intra-group comparisons and the Mann-Whitney U for inter-group comparisons. There were improvements in absolute VO2max (p=0.049), W (p=0.005) and O2pulse (p=0.006) in hyperthermia. In VT1 there was an increase in W (p=0.046), in VO2 in absolute (p=0.025) and relative (p=0.013) values, O2pulse (p=0.006) and VE (p=0.028) in hyperthermia. While W increased in hyperthermia (p=0.022) at VT2. The results suggest that passive and intervallic acclimation at high temperatures improves performance in hyperthermia. This protocol could be implemented in athletes when they have to compete in hot environments.

Aerobic capacity and respiratory patterns are better in recreational basketball-engaged university students than age-matched untrained males

Abstract Study aim: To asses and compare the aerobic capacity and respiratory parameters in recreational basketball-engaged university students with age-matched untrained young adults. Material and methods: A total of 30 subjects were selected to took part in the study based on recreational-basketball activity level and were assigned to a basketball (BG: n = 15, age 22.86 ± 1.35 yrs., body height 185.07 ± 5.95 cm, body weight 81.21 ± 6.15 kg) and untrained group (UG: n = 15, age 22.60 ± 1.50 yrs., body height 181.53 ± 6.11 cm, body weight 76.89 ± 7.30 kg). Inspiratory vital capacity (IVC), forced expiration volume (FEV1), FEV1/IVC ratio, maximal oxygen consumption (VO2max), ventilatory threshold (VO2VT) and time to exhaustion, were measured in all subjects. Student T-test for independent Sample and Cohen’s d as the measure of the effect size were calculated. Results: Recreational basketball-engaged students (EG) reached significantly greater IVC (t = 7.240, p < 0.001, d = 1.854), FEV1 (t = 10.852, p < 0.001, d = 2.834), FEV1/IVC ratio (t = 6.370, p < 0.001, d = 3.920), maximal oxygen consumption (t = 9.039, p < 0.001, d = 3.310), ventilatory threshold (t = 9.859, p < 0.001, d = 3.607) and time to exhaustion (t = 12.361, p < 0.001, d = 4.515) compared to UG. Conclusions: Long-term exposure to recreational basketball leads to adaptive changes in aerobic and respiratory parameters in male university students.

Influence of body mass index and weight lifting on bicep brachii muscle and distal bicep tendon stiffness evaluated using ultrasound elastography

BackgroundThis study aimed to investigate the relationship between stiffness of the bicep brachii muscle (BBM) and distal bicep tendon (DBT) and effects of weight lifting (pre- to post-workout changes) among groups with different body mass indexes (BMI).MethodsParticipants were divided into four groups according to BMI: A, underweight (< 18.5 kg/m2); B, normal (18.5–24.9 kg/m2); C, overweight (25.0–29.9 kg/m2); and D, obese (> 30.0 kg/m2). All participants were males who were untrained and had sedentary lifestyle without involvement in sports activities for the past 12 months. Ultrasonographic measurements to determine muscle and tendon stiffness was performed on the dominant side (i.e., right side) of the upper extremities in all participants.ResultsTwenty-one healthy and untrained males volunteered to participate in this study; 14 were nonsmokers and 7 were smokers. The mean age and BMI were 22.5 ± 1.5 years and 23.8 ± 6.3 kg/m2, respectively. Groups A, B, C, and D had four, ten, four, and three participants, respectively. The BBM thickness did not increase with increase in BMI and was not significantly different (P > .05) between groups. The BBM stiffness was significantly different (all P < .05) from pre- to post-workout values in all groups, whereas DBT stiffness did not follow the same trend.ConclusionsOur study revealed that the BBM thickness is independent of BMI. After weight lifting, BBM stiffness in groups A and B increased for BBM compared to those in groups C and D. A similar trend was also recorded for DBT. Weight lifting in concentric and eccentric motions affects the stiffness of the BBM and DBT, thus weight lifting plays a role in adjusting the stiffness of the BBM and DBT.Trial registration The study was approved by ethics committee of the College of Applied Medical Sciences (CAMS 080-3839; March 14, 2018).

Low Frequency Severe-Intensity Interval Training Markedly Alters Respiratory Compensation Point During Incremental Exercise in Untrained Male.

This study investigated the effect of low-frequency severe-intensity interval training on the respiratory compensation point (RCP) during incremental exercise test. Eighteen healthy males (age; 20.7 ± 2.2 years, range 18 to 29 years, height; 174.0 ± 5.6 cm, weight; 68.8 ± 13.5 kg) were randomly assigned to an interval training group or a control group. Interval training was conducted once weekly for 3 months. Each session consisted of three bouts of bicycle ergometer exercise at 80% maximum work rate until volitional fatigue. Before (baseline) and after the 3-month intervention, incremental exercise test was performed on a bicycle ergometer for determination of ventilatory threshold (VT), RCP, and peak oxygen consumption (V̇O2 peak). The training program resulted in significant increases of V̇O2 peak (+ 14%, p < 0.001, = 0.437), oxygen consumption (V̇O2) at VT (+ 18%, p < 0.001, = 0.749) and RCP (+ 15%, p = 0.03, = 0.239) during incremental exercise test in the training group. Furthermore, a significant positive correlation was observed between the increase in V̇O2 peak and increase in V̇O2 at RCP after intervention (r = 0.87, p = 0.002) in the training group. Tidal volumes at VT (p = 0.04, = 0.270) and RCP (p = 0.01, = 0.370) also increased significantly after intervention compared to baseline. Low-frequency severe-intensity interval training induced a shift in RCP toward higher work rate accompanied by higher tidal volume during incremental exercise test.

The Effect Of Continuous Energy Restriction Vs Intermittent Fasting, With Resistance Training, On Lean Mass

PURPOSE: To determine if two energy restricted diets (continuous energy restriction (CER) and 5:2 intermittent fasting (IF)) combined with resistance training (RT) results in lean body mass (LBM) retention while reducing bodyweight. METHODS: Thirty-four young, untrained males and females were randomised to undertake the following diets for 12 weeks: CER (consume 80% of estimated energy requirements (EER) every day), or IF (consume approximately 30% of EER twice per week on fast days and 100% of EER every other day). Fast days included meals of protein shakes, a soup and vegetables. Both groups aimed to be isocaloric with an average energy restriction of 20% EER, and isonitrogenous consuming an average protein intake of 1.5 grams per kilogram of bodyweight per day. Both groups completed 2 supervised RT sessions and 1 unsupervised workout per week. The IF group completed their exercise on non-fast days. Body composition was assessed by dual x-ray absorptiometry. Data was analysed using an intention-to-treat linear mixed model, assuming AR(1) dependence across time. In addition, a change analysis was conducted for participants who completed both the baseline and 12 week assessments. RESULTS: For females, bodyweight was significantly reduced (mean decrease 3.1%, p=0.009), and LBM significantly increased (mean increase 5.8%, p<0.001), with no difference observed between diets. Similarly for men, there was no significant diet effect on bodyweight; both groups experienced an overall reduction of 6.3% (p<0.001). Combined, men in both diet groups experienced a significant increase in LBM (mean increase 1.4%, p=0.021), however there was a trend towards a greater increase in LBM in the IF compared to the CER group (mean increase CER = 0.7%, IF = 2.0%). CONCLUSIONS: Across both diet groups, males and females experienced a significant reduction in bodyweight while, on average, increasing LBM. Neither diet was more effective for bodyweight reduction, however there was a trend towards greater LBM accrual in IF compared to CER males. Gender specific responses to the intervention were evident, with a greater increase in LBM for females. Moderate energy restriction with high protein intake and RT can lead to concomitant weight loss and LBM accrual.

Elastographic Measurement of Strain Ratio in Finger Tendons of Weight Lifters and Non-Weight Lifters

This study aimed to determine the difference in stiffness and thickness of finger tendons between individuals who performed weight lifting (trained subjects) and those who did not perform weightlifting (untrained subjects) as well as provide real-time diagnosis of tendon stiffness. The study was divided into two groups according to their physical activity level. Individuals who performed training for their upper body for a minimum of 30 minutes, 5 days a week for at least 6 months were categorized as trained individuals, whereas those who did not train were categorized as untrained individuals. Tendon strain ratio and thickness of the index and middle fingers and body mass index (BMI) of trained and untrained adult males were measured. A total of 20 healthy individuals were enrolled for the study. Untrained individuals tended to have higher strain ratios than trained individuals. Tendon thickness between the groups was slightly different. Increased BMI was found in untrained individuals. Trained individuals had stiffer finger tendons than untrained individuals. Different activities, sedentary lifestyles or lifting weight can substantially affect the properties and size of the tendon, which can lead to strengthening or weakening of the finger tendon.

Resistance Exercise in a Hot Environment Alters Serum Markers in Untrained Males.

Purpose: We examined the effects of moderate resistance exercise (RE) on serum cortisol, testosterone, extracellular heat shock protein (HSP70), and interleukin (IL)-6 and IL-15 concentrations in untrained males in a hot environment.Methods: Ten untrained young males (26 ± 3 years; 75.8 ± 6 kg; 177.4 ± 5.3 cm) performed two series of full body RE [3 sets of 8 to 10 repetitions, 30–60 s recovery between series with 70% of one maximal repetition (1-RM), with a rest period of 1 to 3 min between exercises] carried out in a random order in both heated (∼35°C) and thermoneutral (22°C) conditions. Serum concentrations of testosterone, cortisol, HSP70, and IL-6 and IL-15 were measured before, at the end, and 1 h after RE sessions. Participants in both groups consumed 4 ml of water/kg body mass every 15 min.Results: There were time-related changes in testosterone, HSP70, and IL-6 (P < 0.001), and cortisol and IL-15 (P < 0.05). Levels of cortisol, HSP70, and IL-6 increased immediately for RE at 35°C, and testosterone and IL-15 levels were decreased. Changes in serum testosterone, HSP70, cortisol, and IL-15 and IL-6 levels were reversed after 1 h. A significant time × condition interaction was observed for IL-15 and HSP70 (P < 0.001), cortisol and IL-6 (P < 0.05), but not for testosterone (P > 0.05).Conclusion: RE in a heated environment may not be appropriate for achieving muscle adaptations due to acute changes of hormonal and inflammatory markers.

Effects of twelve weeks' aerobic training on motor cortex excitability.

Regular physical activity or aerobic exercise is well known to increase brain plasticity. Recent studies have reported that aerobic exercise enhances neuroplasticity and motor learning. The aim of this study was to investigate if 12 weeks' aerobic training can modify cortical excitability and motor evoked potential (MEP) responses. Fifteen untrained males were recruited. Cortical excitability was investigated using TMS. VO2<inf>max</inf> was estimated using Cooper's test. Aerobic intervention lasted 12 weeks. The subjects performed a 6-week supervised aerobic workout, 3 times a week, at 60-75% of their maximum heart rate (HR<inf>max</inf>). Over the following 6 weeks, they performed a supervised aerobic workout 3 times a week at 70-75% of FC<inf>max</inf>. After 8 weeks of aerobic training there was a significant increase of distance covered during Cooper's test (P<0.001) and a significant increase of VO2<inf>max</inf> (P<0.001); there was also an improvement in resting motor threshold (rMT decreased from 60.5±6.6% [T0] to 55.8±5.9% [T2]; P<0.001), motor evoked potential latency decreased (from 25.3±0.8 ms [T0] to 24.1±0.8 ms [T2]; P<0.001), and motor evoked potential amplitude increased (from 0.58±0.09 mV [T0] to 0.65±0.08 mV [T2]; P<0.001). Furthermore, after 12 weeks' aerobic training there were improvements in all parameters. This study shows that aerobic activity seems to induce changes in cortical excitability if performed for a period longer than 4 weeks, in addition to typical cardiorespiratory benefits in previously untrained males.

Nocebo Effects on Perceived Muscle Soreness and Exercise Performance Following Unaccustomed Resistance Exercise: A Pilot Study.

The purpose of this study was to investigate the effects of nocebo administration on perceived soreness and exercise performance following unaccustomed resistance exercise. Untrained males were randomly assigned to one of two treatments: (1) control or (2) negative-belief. For the negative-belief group, participants were given a capsule before exercise containing 400 mg of an inert substance (gluten-free cornstarch) and were told the supplement would increase muscle soreness. The control group received no treatment. An algometer and pain scale was used to obtain soreness, and a goniometer was used to measure elbow range of motion (ROM). Participants completed an eccentric bicep curl pyramid with their non-dominant arm. Rate of perceived exertion (RPE) and repetitions were recorded. Then, 48 h after the initial exercise bout, participants repeated all procedures. Perceived soreness, ROM, average RPE, and total repetitions performed were analyzed. Perceived soreness was significantly higher in both control and negative-belief groups 48 h after exercise (p < 0.001; η2 = 0.23). ROM was significantly lower 48 h post in the negative-belief group (p = 0.004; d = 1.83) while no differences existed for controls (p = 0.999; d = 0.16). Average RPE was unaffected between groups (p = 0.282; η2 = 0.07). Total repetitions were significantly lower 48 h post in the negative-belief group (p < 0.001; d = 2.51) while no differences existed for the controls (p = 0.999; d = 0.08). Findings suggest that 48 h after unaccustomed resistance exercise, negative expectation does not worsen soreness but hinders ROM and exercise performance.

Moderate-Intensity Strength Exercise to Exhaustion Results in More Pronounced Signaling Changes in Skeletal Muscles of Strength-Trained Compared With Untrained Individuals.

Lysenko, EA, Popov, DV, Vepkhvadze, TF, Sharova, AP, and Vinogradova, OL. Moderate-intensity strength exercise to exhaustion results in more pronounced signaling changes in skeletal muscles of strength-trained compared with untrained individuals. J Strength Cond Res 34(4): 1103-1112, 2020-The aim of our investigation was to compare the response pattern of signaling proteins and genes regulating protein synthesis and degradation in skeletal muscle after strength exercise sessions performed to volitional fatigue in strength-trained and untrained males. Eight healthy recreationally active males and 8 power-lifting athletes performed 4 sets of unilateral leg presses to exhaustion (65% 1 repetition maximum). Biopsy samples of m. vastus lateralis were obtained before, 1 and 5 hours after cessation of exercise. Phosphorylation of p70S6k, 4EBP1, and ACC increased, whereas phosphorylation of eEF2 and FOXO1 decreased only in the trained group after exercise. Expression of DDIT4, MURF1, and FOXO1 mRNAs increased and expression of MSTN mRNA decreased also only in the trained group after exercise. In conclusion, moderate-intensity strength exercise performed to volitional fatigue changed the phosphorylation status of mTORC1 downstream signaling molecules and markers of ubiquitin-proteasome system activation in trained individuals, suggesting activation of protein synthesis and degradation. In contrast to the trained group, signaling responses in the untrained group were considerably less pronounced. It can be assumed that the slowdown in muscle mass gain as the athletes increase in qualification cannot be associated with a decrease in the sensitivity of systems regulating protein metabolism, but possibly with inadequate intake or assimilation of nutrients necessary for anabolism. Perhaps, the intake of highly digestible protein or protein-carbohydrate dietary supplements could contribute to the increase in muscle mass in strength athletes.

Effects of Aerobic-, Anaerobic- and Combined-Based Exercises on Plasma Oxidative Stress Biomarkers in Healthy Untrained Young Adults.

Currently, it is well accepted that physical exercise-induced oxidative stress may damage biological structures and impair cellular functions. However, it is still unclear which type of exercise results in the greatest oxidative stress responses among a healthy untrained population. The aim of the present study was to compare the acute oxidative stress response (i.e., 0 to 20 min) following different types of exercise (anaerobic, aerobic, and combined). Ten healthy, untrained males (19.5 ± 1.7 years) performed three randomized exercise bouts: anaerobic (30 s Wingate test), aerobic (30 min at 60% maximal aerobic power (MAP)) or combined (anaerobic and aerobic). Venous blood samples were collected before, as well as at 0 (P0), 5 (P5), 10 (P10), and 20 (P20) min after each session. Rates of malondialdehyde (MDA) and antioxidant activities (i.e., glutathione peroxidase (GPX), superoxide dismutase (SOD), glutathione reductase (GR), α-tocopherol, and total antioxidant status (TAS)) were assessed. Independent of exercise type, plasma MDA, GPX, SOD, and GR contents increased above baseline, whereas plasma α-tocopherol decreased under baseline after the test sessions (p < 0.05). Aerobic and anaerobic exercises generated faster responses (at P0) when compared to the combined exercise (P5 to P10) for the majority of the tested parameters. Plasma TAS content only increased following the aerobic exercise at P10 (p = 0.03). Five to twenty-minutes post exercise, the highest MDA response was registered in the aerobic condition, and the highest GPX and SOD responses were recorded in the anaerobic (at P5) and aerobic (at P20) conditions (p < 0.05). In conclusion, aerobic, anaerobic, or combined exercises have the potential to acutely increase oxidative stress and antioxidant activities, but with different responses magnitude. These findings confirm that oxidative stress response seems to be dependent on the intensity and the duration of the physical exercise and may help in understanding how varying exercise bouts influence the degree of oxidative stress among healthy untrained young adults.

Effects of resistance training with controlled versus self-selected repetition duration on muscle mass and strength in untrained men.

The aim of this study was to compare the effect of self-selected repetition duration (SELF), with and without volume load (VL) equalized with controlled repetition duration (CON) on muscle strength and hypertrophy in untrained males. We used a within-subjects design in which 20 volunteers (age: 24.7 ± 2.9 years) had one leg randomly assigned to CON (i.e., 2 s concentric, 2 s eccentric) and the other to SELF or to self-selected repetition duration with equalized volume load (SELF-EV). One repetition maximum (1-RM) and muscle cross-sectional area (CSA) were measured at baseline (Pre) and after (Post) resistance training (RT; 2×/wk for 8 weeks). For the main study variables (1-RM and muscle CSA), a mixed-model analysis was performed, assuming repetition duration (SELF, SELF-EV and CON), and time (Pre and Post) as fixed factors and the subjects as random factor for each dependent variable (1-RM and CSA). All RT protocols showed significant increases in values of 1-RM from Pre (CON: 73.7 ± 17.6 kg; SELF: 75.9 ± 17.7 kg; and SELF-EV: 72.6 ± 16.9 kg) to Post (CON: 83.4 ± 19.9 kg, effect size (ES): 0.47; SELF: 84 ± 19.1 kg, ES: 0.43; and SELF-EV: 83.2 ± 19.9 kg, ES: 0.57, P < 0.0001). Muscle CSA values increased for all protocols from Pre (CON: 12.09 ± 3.14 cm2; SELF: 11.91 ± 3.71 cm2; and SELF-EV: 11.93 ± 2.32 cm2) to Post (CON: 13.03 ± 3.25 cm2, ES: 0.29; SELF: 13.2 ± 4.16 cm2, ES: 0.32; and SELF-EV: 13.2 ± 2.35 cm2, ES: 0.53, P < 0.0001). No significant differences between protocols were found for both 1-RM and CSA (P > 0.05). Performing RT with SELF, regardless of VL, was equally effective in inducing increases in muscle strength and hypertrophy compared to CON in untrained men.

Regulation of Proteins in Human Skeletal Muscle: The Role of Transcription

Regular low intensity aerobic exercise (aerobic training) provides effective protection against various metabolic disorders. Here, the roles played by transient transcriptome responses to acute exercise and by changes in baseline gene expression during up-regulation of protein content in human skeletal muscle were investigated after 2 months of aerobic training. Seven untrained males were involved in a 2 month aerobic cycling training program. Mass-spectrometry and RNA sequencing were used to evaluate proteome and transcriptome responses to training and acute exercise. We found that proteins with different functions are regulated differently at the transcriptional level; for example, a training-induced increase in the content of extracellular matrix-related proteins is regulated at the transcriptional level, while an increase in the content of mitochondrial proteins is not. An increase in the skeletal muscle content of several proteins (including mitochondrial proteins) was associated with increased protein stability, which is related to a chaperone-dependent mechanism and/or reduced regulation by proteolysis. These findings increase our understanding of the molecular mechanisms underlying regulation of protein expression in human skeletal muscle subjected to repeated stress (long term aerobic training) and may provide an opportunity to control the expression of specific proteins (e.g., extracellular matrix-related proteins, mitochondrial proteins) through physiological and/or pharmacological approaches.

Balance Alterations Before ACL Surgery and After Rehabilitation

Knee anterior cruciate ligament (ACL) is one of the most often injured knee anatomical structures. There are few studies about balance after ACL rupture, but all results are controversial [1, 2, 3]. Our primary aim was to determine the static and dynamic balance changes before ACL surgery and after rehabilitation. Goals of the study: 1) to investigate and to compare static balance before ACL surgery and after rehabilitation; 2) to investigate and to compare dynamic balance before ACL surgery and after rehabilitation. Ten untrained males participated in this study after ACL rupture (mean ± SD, age 28.4 ± 8.1 years, height – 179.8 ± 8.5 cm, weight – 76.0 ± 14.0 kg). The study was performed in the Lithuanian Academy of Physical Education in the Sports and Movements Science Centre. All subjects where tested before ACL surgery and after 3 months of rehabilitation. Two weeks after the surgery the following rehabilitation was applied: physiotherapy, massage and physiotherapy in the water (3 times per week, 16 times in total). Following these procedures rehabilitation was continued with muscle strength training exercises in a gym. Balance was measured when participant stood on a KISTLER balance platform with open eyes, looking directly into the selected point 2 m away at the eye level, hands on hips. Balance within 20 s while standing on one leg and balance within 15 s after one leg hop for both healthy and ACL ruptured legs were measured. The results showed that standing on ACL ruptured leg before surgery and after rehabilitation the oscillations were not significantly different, but standing on the healthy leg after rehabilitation significantly improved. Test results after one leg hop on ACL ruptured leg showed that oscillations were significantly greater after rehabilitation. Conclusions: 1. After rehabilitation one leg static balance improved only in non-injured leg. 2. After rehabilitation one leg dynamic balance decreased in injured leg, but increased in non-injured leg.Keywords: anterior cruciate ligament, rehabilitation, static balance, dynamic balance

Differences in Handgrip Strength-Endurance and Muscle Activation Between Young Male Judo Athletes and Untrained Individuals

ABSTRACT Purpose: The aim of this study was to compare strength-endurance handgrip performance and muscle coactivation between judo athletes and untrained young males. Method: The sample was 38 judo athletes and 38 untrained young males, between 12 and 15 years-old. Maturational status was evaluated by age at peak height velocity. A maximal isometric handgrip test (three 5-s repetitions, with 90-s intervals) and an isometric strength-endurance handgrip test (ten 10-s all-out isometric handgrip repetitions, 20-s intervals) was conducted in dominant (D) and nondominant (ND) hands, using a dynamometer with EMG monitor to detect muscle activation. Results: ANCOVA analysis, controlling for maturational status, showed that judo athletes had higher values of maximal absolute (D = 33.6 ± 8.9 kgf vs 29.1 ± 9.0 kgf; ND = 33.8 ± 9.9 kgf vs 28.1 ± 8.1 kgf) and relative strength to body mass (D = 0.64 ± 0.12 kg/kgf vs 0.57 ± 0.13 kg/kgf; ND = 0.64 ± 0.16 kg/kgf vs 0.56 ± 0.14 kg/kgf). Moreover, judo athletes presented lower strength mean fatigue index (33.2 ± 6.9 % vs 37.9 ± 8.7 %) and muscle coactivation (48 ± 19.8 % vs 57.5 ± 22 %), only in the dominant hand, during the isometric strength-endurance handgrip test. During all repetitions of isometric endurance test there were no group or interaction between factors effects for absolute strength, relative strength and muscle coactivation. Conclusion: In summary, judo athletes present higher maximal absolute and relative strength and strength-endurance performance, concomitantly with decreased muscles co-activation (primary in dominant hand) during handgrip tests.

Reproducibility of Internal and External Training Load During Recreational Small-Sided Football Games

ABSTRACT Purpose: The aim of this study was to evaluate the reproducibility of internal and external load parameters during recreational small-sided football games. Methods: Ten healthy untrained young adult males (age: 20.2 ± 1.9 yr, body mass: 69.2 ± 6.3 kg, height: 175.4 ± 5.9 cm, body fat: 19.7 ± 5.2%) performed two 2 × 20-min sessions of four versus four plus goalkeeper small-sided games (SSG) 1 week apart on a standard, outdoor, 40 × 20-m artificial grass pitch. Twelve external (total distance, peak speed, player load, work rate and distance covered at 0–2, 2–5, 5–7, 7–9, 9–13, 13–16, 16–20 and >20 km/h) and seven internal load parameters (heart rate and time spent in different heart rate zones [<70%, 71–80%, 81–90%, 91–95%, 96–100%, 91–100%]) were measured. Reproducibility was reported as intraclass coefficient correlation (ICC), the coefficient of variation (CV), and the typical error of measurements (TE). Results: No statistical differences (p> .05) between sessions were found in any measures. Minimal test-retest variability was noted for mean and peak heart rate (HRpeak) relative to HRpeak with CV values of 3.4% and 2.6%, respectively. Acceptable variability (CV<10%) was demonstrated for total distance covered, distance covered at 2–5 km/h, and peak speed. Distance covered in different speed zones (CV = 15.7–47.6%) and percentage of time in each HR zone showed large-to-very large variability (CV = 36.2–128.4%). Mean heart rate (HRmean), HRpeak, distance covered at 5–7, 13–16 and >20 km/h, and percentage of time above 95%HRpeak were the most reliable variables (ICC = 0.74–0.79), followed by total distance covered, peak speed, and percentage of time at 80–90% HRpeak (ICC = 0.39–0.67). The lowest reliability was observed for distance covered in the moderate speed zones 7–9 km/h (ICC = 0.12) and 9–13 km/h (ICC = −0.09), and percentage of time at 70–80% HRpeak (ICC = −0.01). Conclusions: Small-sided games can be used when planning training-induced exercise responses in relation to total distance covered, peak speed, and mean heart rate. This evidence further supports the use of SSG when organizing recreational football training, in young adult males, with the purpose of improving health profile due to the high reproducibility of HRmean and total distance covered.

Use of prefrontal cortex activity as a measure of learning curve in surgical novices: results of a single blind randomised controlled trial.

Neurobiological feedback in surgical training could translate to better educational outcomes such as measures of learning curve. This work examined the variation in brain activation of medical students when performing laparoscopic tasks before and after a training workshop, using functional near-infrared spectroscopy (fNIRS). This single blind randomised controlled trial examined the prefrontal cortex activity (PFCA) differences in two groups of novice medical students during the acquisition of four laparoscopic tasks. Both groups were shown a basic tutorial video, with the "Trained-group" receiving an additional standardised one-to-one training on the tasks. The PFCA was measured pre- and post-intervention using a portable fNIRS device and reported as mean total oxygenated hemoglobin (HbOµm). Primary outcome of the study is the difference in HbOµm between post- and pre-intervention readings for each of the four laparoscopic tasks. The pre- and post-intervention laparoscopic tasks were recorded and assessed by two blinded individual assessors for objective scores of the performance. 16 Trained and 16 Untrained, right-handed medical students with an equal sex distribution and comparable age distribution were recruited. Trained group had an attenuated left PFCA in the "Precision cutting" (p = 0.007) task compared to the Untrained group. Subgroup analysis by sex revealed attenuation in left PFCA in Trained females compared to Untrained females across two laparoscopic tasks: "Peg transfer" (p = 0.005) and "Precisioncutting" (p = 0.003). No significant PFCA attenuation was found in male students who underwent training compared to Untrained males. A standardised laparoscopic training workshop promoted greater PFCA attenuation in female medical students compared to males. This suggests that female and male students respond differently to the same instructional approach. Implications include a greater focus on one-to-one surgical training for female students and use of PFCA attenuation as a form of neurobiological feedback in surgical training.

Effects of 12 weeks combined weight and chain versus combined weight and elastic band variable resistance training on upper and lower body muscular strength and endurance among untrained males in Iran

Several studies have shown a positive association between variable resistance training and improvement of muscular performance. However, the most effective type of variable resistance training to improve muscular performance (such as; strength and endurance) in untrained individuals remains unclear. The objective of this research was to examine the effects of 12 weeks combined weight and chain versus combined weight and elastic band variable resistance training on muscular strength and endurance among untrained male adults. Fifty healthy untrained males (age: 21.5 ± 1.95 years) were randomly selected and assigned into three groups: combined weight and chain (WC), combined weight and elastic band (WE), and free-weight (CG). From week 1 until week 12 all groups trained with 3 to 4 sets of 8 - 12 repetitions with 70% to 80% of 1RM for 2 days per week. Approximately 65% of the resistance was provided by free-weights and 35% of the resistance was provided by chains and elastic bands for the WC and WE groups. Upper and lower body muscular strength and endurance using one-repetition maximum, and maximum repetitions were measured before, in the middle and after the intervention. Results reported there were significant increases in upper and lower body muscular strength and endurance in all groups in the middle and after the intervention (p &lt; 0.05), and these variables increased more and faster significantly in WC and WE groups compared with CG group. Finally, although in the middle and after the intervention there were not significant differences in upper and lower body muscular strength and endurance between WE and WC groups (p &gt; 0.05), the results showed WE variable resistance training had a better effect insignificantly to improve upper and lower body muscular strength and endurance in the middle and after 12 weeks of variable resistance training among untrained males.

Comparison between two methods of variable resistance training on body composition, muscular strength and functional capacity among untrained males

Several studies have shown a positive association between variable resistance training and improvement of muscular performance. However, the effect of variable resistance training to improve body composition in untrained individuals remains unclear. The objective of this research was to examine the comparison of 12 weeks combined weight and chain versus combined weight and elastic band variable resistance training on body composition among untrained male adults. Fifty healthy untrained males (age: 21.5 ± 1.95 years) were randomly selected and assigned into three groups: combined weight and chain (WC), combined weight and elastic band (WE), and free-weight (CG). All groups trained with 3 sets of 8 - 12 repetitions with 70% to 80% of 1RM for 2 days per week. Approximately 65% of the resistance was provided by free-weights and 35% of the resistance was provided by chains and elastic bands for the WC and WE groups. Body fat mass (FM) and body fat free mass (FFM) using bioelectrical impedance analyser were measured before, in the middle and after the intervention. Results reported although in the middle and after the intervention all groups showed a significant reduction in FM and significant gained in FFM (p &lt; 0.05), there were not significant differences in FM and FFM among all groups (p &gt; 0.05). However, FM decreased and FFM increased more insignificantly in WE and WC groups compared with CG group, and also FM decreased and FFM increased more insignificantly in WE group to compare with WC group during and after 12 weeks of variable resistance training (p &gt; 0.05). The results showed WE variable resistance training had a better effect insignificantly to improve body composition in the middle and after 12 weeks of variable resistance training among untrained male adults.